- In electricity, charge
(q,Q) plays the same
role as mass does in mechanics.
- There are two kinds of charges :
positive and negative.
- If an object contains equal amounts of positive
and negative charges the object is electrically neutral,
it has no net charge.
- An object is said to be charged
if it has a net charge.
- Charged objects interact by exerting forces on
- The force between stationary charges is called the
- Charges with the same
electrical sign repel each other, and
charges with opposite electrical signs attract each other.
- The SI unit of charge is the Coulomb [C].
- Any positive or negative charge (q) can be written
as : q = n e , n = ±1, ±2, …
where e = 1.6 x 10-19
C is the magnitude of the charge of the electron.
- Thus, electric charge can have only discrete
values, and thus, it is quantized.
- Electric charge is always conserved. Charge can
not be created, but rather, transferred.